Engine starter gearing



April M, 1940- M. P. WHITNEY ENGINE STARTER GEARING Filed Feb. 26, 1938 INVENTOR.

Patented Apr. 16, 1940 ENGINE STARTER GEARING Maurice P. Whitney, Elmira, N. Y., assignor, byu mesne assignments, to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application February 26', 1938, Serial No. 192,824

2 Claims. (01. 74-6) The present invention relates to engine starter gearing and more particularly to manually operable devices for connecting a starting motor to a member of an engine to be started.

It is an object of the present invention to provide novel manually shiftable starter gearing which is positive and reliable in action while being simple and economical in construction.

It is another object to provide such a device incorporating an overrunning clutch which is small and light but is arranged to carry heavy torque without undue localized stresses.

It is a further object to provide such a device which is so constructed as to engage positively without jamming, and to overrun quietly and freely.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. l is a side elevation partly in section of one preferred embodiment of the invention;

Fig. 2 is a section taken substantially on the line 2--2 of Fig 1;

Fig. 3 is a view similar to Fig. 1 of, a second embodiment of the invention;

Fig. 4 is a section takensubstantially on the line 4-4 of Fig. 3;

Fig, 5 is a detail in side elevation partly in section of structure similar to Fig. 1 with a rearrangement of the clutch controlling features;

and

Fig. 6 is a section taken substantially on the line 6--6 of Fig. 5. i

In Fig. 1 of the drawing, there is illustrated a power shaft which may be the extended armature shaft of the starting motor, not shown, on which is journalled a driving member in the form of a pinion 2 with freedom for slidingmovement on the shaft l into and out of engagement with a member such as a flywheel gear, not illustrated, of an engine to be started.

Means for actuating the pinion 2 are provided including a hollow screw shaft 3 splined as indicated at 4 on the power shaft A driving clutch plate 5 is threaded on the hollow shaft 3 as indicated at 6, and a cooperating driven clutch plate I is non-rotatably connected to a barrel member 9 by means of driving lugs 8 engaging in slots H5 in the barrel. The barrel is rigidly fixed to the pinion 2 as indicated at H. A stop nut l2 fixed on the end of the screw shaft 3 is arranged to form an abutment for the driven clutch plate 1, and longitudinal movement of the barrel with respect to the driven clutch plate is prevented by means of a spacing sleeve I3 seated in the barrel against the clutch member, retained by suitable means such as a split lock ring l4 and prevented from rotation in the barrel by outturned flanges ['5 *engagingin one of the slots l6 inthe barrel (Fig. 2).

Means for controllingthe threaded clutch Yielding means for sliding the pinion 2 and screw shaft 3 and their associated parts on the power shaft I soas tobring the pinion into and out of operative position, are provided in the form of' a shifting collar" 2| slidably mounted on the smooth portion 22 of the screw shaft and maintained in engagement with a locking ring 23 on the screw shaft by means of a spring member 24 bearing against a shoulder 25 formed at the end of the threaded portion of said shaft.

In order to insure positive engagement of the clutch p1ates5 and 1 without jamming action, the opposing faces of such clutch members are provided with interengaging lugs and recesses 26 and 21 respectively.

In the operation of this invention, sliding movement is imparted to the shift collar 2| by any' suitable shifting means such as a manually operated fork engaging therein. When the pinion Z-has thus been. causedto engage the flywheel gear of the engine to be started, the starting motor is energized in the usual manner, causing rotation of the power shaft I. This rotation is'transmitted through the splines 4 to the screw shaft 3, and since the threaded clutch plate 5 is. initially prevented from rotation by the frictional engagement of the spring ring I! in the grooveFlB, said clutch plate threads itself along the screw shaft until the clutch elements 26 thereof engage ,the clutch elements 21 of the driven clutch plate 1, whereupon the pinion 2 is positively connected for rotation with the power shaft I. T

When the engine starts, the acceleration of the pinion 2 causes it .to overrun the power shaft 1, whereby, the barrel 9 accelerates 'the threaded clutch member 5, first by the positive connection of the. clutch (elements 21, 25', and

embodiment 'of the driving clutch plate 34.

slid back to their idle positions on the power shaft In the embodiment of theinvention illustrated in Figs. 3 and 4, a hollow shaft 28 is splined as indicated at 29 on a power shaft 3|, and is fixed in any suitable manner as at 32 toabarre member 33.

rotatably mounted in the barrel 33 as by means of radial lugs 35 engaging in slots 36 in the barrel, and is retained in the barrel by means of .a illustrated, the spring friction ring which conspacing ring 3? locked in the barrel by a split ring 38 and having outturned flanges 39 (Fig. 4) engaging in one of the slots 35 to prevent relative rotationbetween the ring and barrel.

A pinion 4| having a hollow threaded shaft 42 formed as an extension thereof or suitably fixed thereto, is slidably journalled on the power shaft 3|, and a driven clutch plate 43 is threaded on the shaft 42 in position to cooperate with the The idle position of the clutch plate is preferably determined by abruptly terminating the threads of shaft 42 adjacent the pinion 4|, or the pinion itself may form the stop for theficlutch plate when the pinion and shaft 42 are formedseparately, any suitable spacing means being interposed if deemed desirable. A stop nut 44 is fixed onthe endof the shaft 42 to serve as an abutment for the driving clutch plate 34. Cooperating lugs and recesses 45 and 46 are provided on theopposing faces of the clutch elements 34 and 43 in order to establish a positive non-jamming, driving connection therebetween.

Means for controlling the threaded clutch plate 43 is provided in the form of a spring ring 4'! bearing frictionally in a groove 48 in the periphery of the clutch plate 43 and having an outturned end 49 engaging in one of the slots 36 of the barrel.

Means for sliding the pinion and splined shaft assembly on the power shaft 3| is provided in the form of a shifting collar 5| slidably mounted on the splined shaft 28 and yieldably held against a lock ring 52 seated in said'splined shaft, by

means of a spring 53.

' In the operation of this embodiment of the invention, the pinion 4| is meshed with the en.- gine ring gear, not illustrated, by any suitable shifting means such as a. manually operated fork engaging the shift collar 5|. Rotation of the power shaft 3| by the starting motor is thereupon. transmitted. through the splines 29 and shaft 28 to the barrel 33 which rotates the driving clutch plate 34 by reason of its positive anchorage therein, and rotates the driven clutch plate 43 through its frictional connection with the spring ring 41. Since the pinion 4| is at this time prevented from rotation by its engagement with the engine member, the driven clutch plate 43 is thus threaded into engagement with the driving clutch plate 34, whereupon the pinion 4| is positively connected to the barrel 33 for rotation therewith.

When the engine startsthe overrunningaction of the pinion 4| with its screw shaft 42 causes thedriven clutch plate '43.to thread itself away from the driving clutch plate 34 to its -idle posi- A driving clutch plate 34 is nontion as defined by the ends of the threads on shaft 42, or the end of pinion 4| as above set forth. The pinion, screw shaft and driven clutch plate thereupon overrun freely until the parts are returned to their idle positions by the shifting means.

The embodiment of the invention illustrated in Figs. 5 and 6 is similar to that shown in Figs. 1 and 2 with the excepticn'of the form of the controlling means for the threaded clutch plate, and

the various elements of the structure are accordingly numbered as in Figs. 1 and 2. In this form of the invention, however, the spring ring 9 la is anchored in the groove |3a in the threaded clutch plate 5 by means of its inturned end Na, and the ring bears frictionally on the interior of the spacing ring it as best seen in Fig. 6.

In the various embodiments of the invention while causing-the clutch members to engage:

Thus in Fig. 2 of the drawing the rotation of the power shaft is assumedto be in a clockwise direction whereby in the first embodiment of the invention, thefriction ring I! contracts on the threaded clutch plate 5 astorque is transmitted therethrough. In Fig. 4 the friction ring 4? is similarly actuated by the counterclockwise rotation of the barrel 33 to frictionally gripv the threaded clutch plate 23. In Fig. 6 the friction ring Ila. expands into gripping engagement with the interior of the spacing ring I3 in like manner responsiveto counterclockwise rotation of the threaded clutch plate 5.

It will be readily appreciated. that there is here provided a starter gearing which is positive'in action without jamming and which overruns freely and quietly.

Although certain embodiments of the invention have been shown and'described in detail, it will be understood that other embodiments are pos-' sible and various changes may be made in the construction and arrangement ofthe parts without departing from the spirit of the invention as defined in the claims appended'hereto.

What is claimed is:

1. In an engine starter, a power shaft, a hollow shaft splined thereon; a pinion slidably journalled on the power shaft, and'an overrunning clutch connection. between the hollow shaft-and pinion including a barrel member fixed to one of said members, a screw shaft fixed to the other,

said barrel member having a plurality of longi-' tudinal slots, a clutch plate in the barrel having radial lugs traversing said slots, a clutch plate threaded on the screw shaft, said clutch plates having mating lugs and recesses, a sleeve anchored in the barrel in abutting relation to the first clutch plate, and a control member for the threaded clutch plate in the form of an elastic split ring frictionally connecting the threaded clutch plate to the sleeve, said ring being anchored at one'end to one of said members being arranged to grip the other member with a self-tightening action when the power is rotated to crank the engine. 2. In an engine starter, a power shaft, a hollow shaft splined thereon, a pinion slidably jour nailed on the power shaft, and an overrunning clutch connection between the hollow shaft and pinion including a barrel member fixed to one of said members, a. screw shaft fixed to the other,

said barrel member having a plurality of longitudinal slots,a clutch plate in the barrel having radial lugs traversing said slots, a clutch plate threaded on the screw shaft, said clutch plates having mating lugs and recesses, a split sleeve anchored in the barrel in abutting relatien to the first clutch plate, having flanges engaging in a slot or" the barrel to prevent rotation of the sleeve in the barrel, and a control member for the threaded clutch plate in the form 0f an elastic split ring frictionally connecting the threaded clutch plate to the sleeve, said ring having an outturned end extending into said slot of the barrel and being seated in a groove in the periphery of the threaded clutch plate and arranged to grip said clutch plate when the power shaft is rotated to crank the engine.

MAURICE P. WHITNEY. 

